Self-cleaning filter



(No Model.)

C. I'. H. FRANKE 8v I'. BUCHHORN. SELF CLEANING FILTER.

Patented Nov. 16, 1897.

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UNITED STATES PATENT CEETCE.

CI-IARLES F. H. FRANKE AND FREDERICK BUCHHORN, OF CHICAGO,

ILLINOIS.

SELF-CLEANING FILTER.

SPECIFICATION forming part of Letters Patent N 0.593,573, dated November 16, 1897. Application filed January 11, 1897. Serial No. 618,892. (No model.)

To @ZZ whom, it may concern:

Be it known that we, CHARLES, F. H. FRANKE and FREDERICK BUCHHORN, citizens of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented an Improvement in Self-Cleaning Filters, of which the following is a specification.

For a complete description of our invention reference is made to the accompanying drawings, forming a part of this specification, and in which-` Figure lis a complete sectional view showing all parts. Fig. 2 is a horizontal view, part in section. Y Fig. 3 is an elevation of our improved collar for clamping the filter to the faucet. Fig. 4 is a plan of the same. Fig. 5 is a horizontal section of the waste-outlet of our filter, taken on the line a: :c and looking in the direction of the arrow. Fig. G is an elevation of the valve of our filter and its controlling-spring. Fig. 7 is an elevation of the thumb-ring for controlling said valve, and Fig. 8 is a plan of the same.

Our invention has for its object the production of an eiicient self-cleaning filter of simple and durable construction.

A further object is to provide a means for clamping the filter to a faucet or pipe of any size without screw-threading or otherwise altering the nozzle of said pipe or faucet.

The outer casing of our filter is composed of the parts A, B, and C. The parts B and and C are preferably of brass, turned or spun out in such manner as to iit snugly over the cylindrical tube A, of similar material.

' Through the center of this casing passes a metallic tube H, having near its upper end a shoulder engaging on the upper edge of the centrally-disposed hole in the piece B.

C is a ring tting into the enlarged portion of the cup-shaped piece C and having lugs c c projecting from its inner periphery. Attached to these lugs by the screws b b is arod D, having an opening in its center, said opening being screw-threaded to receive the lower end of the above-mentioned tube H. Between the cylindrical piece A and the upper part of the case B is a thin washer q, of rubber. Fitting in the annular groove formed between the outer periphery of the piece C and the inner periphery of the ring C is a similar rubber washer o. When the tube His screwed firmly into the opening in the rod D, all of the parts herein described are bound firmly together and all the external joints are rendered tight by virtue of the rubber washers q and 0. Resting against the inner side of the washer q is a metallic ring E, on the lower side of which is fastened a screen L of finewire gauze, through a hole in the center of which passes the tube I-I. On the lower side of this gauze screen is placed a washer Q of thin silk cloth.

Above the rod D is a leaf-spring R, which surrounds the tube II and bears against the rod D on its lower side and against a plate P, of brass, on its upper side. This plate of brass has an annular depression near the circumference of its upper face in which rests the washer r, preferably of soft rubber. This washer projects beyond the edge of the plate and bears against the inner surface of the cylindrical shell A. The plate P is perforated with holes h, tapering from above. On the upper side of the plate P is placed another screen L', of wiregauze, also covered by a washer Q of silk cloth. In the space between the upper and lower screens of wire-gauze and their corresponding coverings of silk cloth is placedthe filtering medium X, consisting, preferably, of raw cotton, but may consist of sand, charcoal, porous stone, spun-glass,wool, or any other suitable material. We have found by careful experiments that raw cotton or cotton which has not been treated in such manner as to remove its natural oil is the most desirable substance for this purpose, as it not only filters well, but will last for years without rotting.

The leaf-spring R, pressing against the under side of the plate P, tends to force it upward and thus maintain the filtering medium in a suitably-compact condition. The function of the silk washers above and below the filtering medium is not only to aid in filtering, but to keep the small particles of the filtering medium from working loose and becoming lost.

The valve V is normally held by the spring S in aposition j ust above the valve-seat,which IOO is in the upper part of the tubular extension N, projecting from the bottom of the case C. The thumb-ring K is clamped to the lower tubular portion NV of the valve V by the screws s' s'. By pulling the thumb-ring K down the valve V is caused to rest in the valve-seat and thus completely close-the opening in the shell C. The strength of the spring S is such as to raise the valve when it is not subjected to pressure from above by the water in the filter, but to allow it to remain closed as long as the water-pressure exists in the filter.

The clamping-sleeve Ghas two lugs Z Zprojecting from its upper end, and between these lugs is a vertical slot. A screw s passes through a hole in one of these lugs and engages a threaded hole in the other in such manner as to contract the diameter of the upper part of the ring when tightened. A slot T is cut at right angles to the axis of the sleeve in such manner as to afford greater flexibility between the lugs Z Z. The lower portion of the sleeve is screw-threaded on its outer surface. This screw-thread may be made to engage with a corresponding thread on the inner portion of the bottom of the enlarged portion of the tubeand against the under side of the projecting portion of the faucet.

The operation of our filter is as follows:

When the water is turned on through the faul cet, it'rushes down through the tube H, around the valve V, and out through the tubular opening N. l until the ring K is manually pulled down, when the valve is closed and the water forced to take another path. The water is now forced upward through the openings h in the plate' I), through the filtering medium X, and into the chambers above, from which it escapes by the tube or nozzle U. The valve V is held4 closed by the water-pressure as long as the water is turned on from above. As soon, however,`as the water is turned off the spring s opens the valve and all the water contained in'the filter is allowed to escape through the lower opening. This rush of water which follows the opening of the valve V carries withv itthe residue collected on the under side ofthe filtering medium X and allows it to drain from the lower chamber. The draining off of the water in-the lter causes a downward suction of air through the nozzle U and the filtering medium X, eectually driving out any sediment that may have worked slightly into the lower portion of the medium X` Vhen the water is againiturned on,'the first rush It is then firmly clamped by means of: The filter may then bev It will continue to take this path of water through the lower chamber D completes the washing out of this chamber.

It has been found that where a filtering medium is inclosed in a vessel having smooth walls a comparatively open path is formed between the wall of the vessel and the filtering medium which often allows dirt and other foreign matter to pass through the filter. The rubber washer r effectually prevents the forming of such a path, and thus entirely avoids this difficulty.

The strength of the spring S may be so adjusted as to admit of the automatic closure of the valve by the water-pressure itself, thus dispensing with the thumb-ring and making the action of the valve entirely automatic. This and many other modifications clearly 'come within the scope of our invention.

Having now fully described our invention, what we claim as new, and desire 4to secure by Letters Patent, is-r 1. A self-cleaning filter comprising a hollow metallic case containin ga filtering medium, a tube leading from the water-supply to a chamber below said filtering medium, a tube for filtered water leading from said caseabove said filtering medium, a tubular opening leading from said case below said filtering medium, a valve having a hollow cylindrical extension projecting through said tubular opening, and a spiral spring surrounding said cylindrical extension and holding the valve normally open but allowing it to close when subj ected to water-pressure, substantially as described.

2. In a filter, ametallic case and a filtering medium contained therein, a tube leading fromY the water -supply to a chamber below said filtering medium, an outlet leading from a chamber above said filtering medium, an outlet leading from the lower chambeiyanda. valve for closing said lower outlet, a thumbring carried on va downwardly-extending projection from said valve and a spiral sprin g surrounding said extension and serving to open said valve when released from water-pressure in the filter, substantially as described.

3. In combination with a filter a slotted sleeve adapted to clamp the end of a water pipe or faucet slightly above its extremity, a. screw-thread on the lower portion of said sleeve, a tube having an inner screw-threaded portion to engage such sleeve and having a shoulder just below said screw-threaded portion, and a ring washer resting in said shoulder and adapted to be clamped against the IOO end of the nozzle when the tube is screwed washers against said filtering medium, atube drawn o after each use of the filter, subleading from the chamber above said lterstantially as described. ing medium, an outlet leading from the chamber below said ltering medium, and a valve 5 for closing said lower outlet while under water-pressure, but adapted to open when said Witnesses: pressure ceases whereby the water and resi- J. W. WRAITH, due in the lower chamber are automatically W. F. DUNHAM. 

